// 居中
.content-middle{
  width: 1200px;
  position: relative;
  margin: 0 auto;
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
  flex-wrap: wrap;
}

.bbs-body{
  margin-top: 6px;
  margin-bottom: 0;
  .bbs-content{
    display: inline-block;
    margin-bottom: 20px;
    max-width: 66.66666%;
    flex: 0 0 66.66667%;
  }
}